Question

an element has atomic number 17.where would you expect this element in the long form of periodic table?why?

Answer 1

Group 17 . It's name is chlorine

Answer 2

An atomic number refers to the number of protons in an atom. The number of neutrons is same as the number of protons. This sum of protons and neutrons is called as the mass number.

Chlorine has an atomic number of 17 and so the mass number is (17 + 17) = 35.

The elements are usually arranged in an ascending order of the atomic number in the Periodic Table. So, Chlorine will be placed at the 17th position in the periodic table and it will belong to group 17. It is located in the third period.
Chlorine is a halogen and it is placed in between Fluorine (F) and Bromine (Br).